2-methyl-7-substituted pyrazolo[1,5-a]pyrimidines: highly regioselective synthesis and bromination

Journal of the Brazilian Chemical Society

Marcos A. P. Martins²  Elisandra Scapin¹  Clarissa P. Frizzo²  Fernanda A. Rosa²  Helio G. Bonacorso²  Nilo Zanatta² 

[1] ,Universidade Federal de Santa Maria Departamento de Química Santa Maria RS ,Brazil

关键词: pyrimidines;    pyrazoles;    pyrazolo[1;    5-a]pyrimidines;    enones;    bromination;   

DOI  :  10.1590/S0103-50532009000200003

来源: SciELO

【 摘 要 】

The reaction of 3-amino-5-methyl-1H-pyrazole with 1,1,1-trichloro-4-alkoxy-3-alken-2-ones [CCl3C(O)CH=C(R¹)OR, where R¹/R = H/Me, Me/Et, Et/Me, Pr/Et, Bu/Me, iso-Bu/Me] or β-dimethylaminovinyl ketones [R²C(O)CH=CHNMe2, where R² = Ph, Ph-4-Me, Ph-4-F, Ph-4-Cl, Ph-4-Br, Ph-4-NO2, fur-2-yl, thien-2-yl, pyrrol-2-yl, pyrid-2-yl], in acetic acid under reflux for 16 hours, furnished highly regioselective the halomethylated pyrazolo[1,5-a]pyrimidines and aryl[heteroaryl]pyrazolo[1,5-a]pyrimidines, respectively. A protocol for the bromination reaction at the 3-position pyrazolo[1,5-a]pyrimidines also was investigated.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License